Breath actuated nebulizer

ABSTRACT

A breath actuated nebulizer for administration of an inhaled medication to a patient is provided with a generally cylindrical body in a horizontal orientation to the patient. Within the body is a Venturi configured to nebulizer a liquid medication in a reservoir. Within the body is a shaft integrated with a baffle and diaphragm that slides horizontally in response to the breathing of a patient. During inhalation by the patient, the diaphragm flexes shifting the baffle over the Venturi, allowing nebulization to occur. When the patient exhales, the diaphragm flexes to a default position in which the baffle is distal to the Venturi, thereby stopping the nebulization. The diaphragm is biased to rest in this default position until the patient inhales again.

FIELD OF THE INVENTION

This disclosure pertains to nebulizers for the administration of inhaledaerosol drugs.

BACKGROUND

In the field of respiratory devices, nebulizers are important devicesused for the inhalation of drugs in the form of an aerosol to patientsin need of a drug administered directly into the lungs. A nebulizeremploys an apparatus that generates an aerosol or mist from a solution(usually an aqueous solution) or suspension of a drug. The mist may bean aerosolized suspension or an atomized suspension of drug, meaningmicro-droplets suspended in air, medical oxygen, or other inhalable gas.The aerosol is conveyed to the mouth and/or nose of a patient andinhaled into the lungs. In some cases, the mist is conveyed to the lungsthrough a mouthpiece. In other cases, the nebulizer may be coupled to aninhalation mask.

Several nebulization technologies are known, including gas-jet,ultrasonic, and vibrating mesh nebulizers. This disclosure pertains togas-jet nebulizers, which operate using a Venturi, wherein a jet ofpressurized gas (air or other suitable gas, such as medical oxygen) isdirected over an orifice on a capillary that is connected to a reservoircontaining a drug in aqueous solution. The Venturi creates a localizedlow pressure zone that draws the drug solution out of the capillaryorifice and into the air jet, where the liquid is atomized by a shearingeffect. Typically, a baffle is employed in the jet effluent to assist inthe formation of appropriate size droplets in the nebulized stream. Inaddition, a baffle prevents large droplets from exiting the device, sothat only aerosol micro-droplets of drug containing solution exit thedevice. Still further, in many nebulizer designs, a baffle may berequired to deflect the low pressure zone created by a Venturi jot overa liquid orifice in communication with the drug reservoir. In suchdesigns, the baffle is required to draw the liquid into the stream ofpressurized gas that causes nebulization of the liquid. An example ofsuch a nebulizer is disclosed in U.S. Pat. No. 4,588,129. The aerosol isthen inhaled by the patient. Typically, the aerosol production iscontinuous, so a vent is typically provided to ensure that the pressuredifferential created by the jet operates continuously and consistently.The drug reservoir in nebulizers is usually a cone, cup, or bowl-shapedvessel into which a sterile aqueous solution of the drug is added.

Other nebulizer methods besides gas-jet nebulizers are known, forexample ultrasonic nebulizers and vibrating mesh nebulizers.

Typical drugs used with nebulizers are drugs for the treatment of asthmaand obstructive pulmonary diseases, but other pulmonary and systematicmedications may be administered by inhalation with nebulizers. Forexample, albuterol (called salbutamol in many countries), used fortreating asthma and bronchospasm, may be administered as a nebulizedsolution. Another example is pentamidino, a drug used to treatPneumocystis carinii pneumonia (PCP) (also called Pneumocystisjirovecii). Many other medications are useful or potentially useful asinhaled drugs and can potentially be used with a nebulizer.

Nebulizers are particularly useful for the administration of inhaleddrugs to small children, elderly, unconscious, or disabled patients whocannot coordinate their breathing or take instruction on the use ofcoordinated inhalation devices, such as a metered dose inhaler. Also,nebulizers may be used with an inhalation mask for patients who cannotuse a mouthpiece to inhale the drug. With a nebulizer, the dose of drugis administered to the patient over a period of several minutes, andpossibly ten to twenty (or more) tidal or slow deep inhalations perminute, so breathing coordination is not required.

Nebulizers are typically equipped with a mouthpiece that a patient caninsert in their mouth, making an airtight seal with their lips whileinhaling through the mouth to ingest the nebulized medication into thelungs. In the case of patients who cannot hold a mouthpiece in theirmouth or close their lips round the mouthpiece to create a seal, aninhalation mask may be used with a nebulizer. An example of such a maskis disclosed in PCT International Application WO 2012/173993.

In breath-actuated nebulizers, nebulization of the drug only occursduring inhalation by the patient. Breath-actuated nebulizers have ameans for stopping the nebulization or flow of aerosol during exhalationor other intervals when the patient is neither inhaling or exhaling.Such devices are known, for example, from Denyer in U.S. Pat. RE40591,and Grychowski et al., in U.S. Pat. Nos. 5,823,179 and 6,644,304. Abreath-actuated nebulizer has been marketed in the United States underthe brand name AEROECLIPSE® by Monaghan Medical, and by Trudell MedicalInternational in other countries.

Breath-actuated nebulizers may have significant advantages overconventional nebulizers. In conventional nebulizers, the drug isaerosolized continuously regardless of whether the patient is inhalingor not. Conventional nebulizers typically are vented to the atmosphere,so aerosol that is not inhaled is vented to the air in front of thepatient. This wastes drug, and exposes others (including caregivers) inthe vicinity to the aerosolized drug. In addition, the dosage isimpossible to precisely determine because of this drug loss. In manycases, these shortcomings are not a problem, due to the low cost ofconventional (continuous) nebulizers, and the low toxicity and low costof drug of many of the drugs used in conventional nebulizers.

However, in the case of expensive drugs or drugs that may be toxic orsensitizing to others in the vicinity of the patient, conventionalnebulizers are much less desirable than a breath-actuated nebulizer.With a breath-actuated nebulizer, the dosage can be precisely metered,and very little of the drug is wasted, since nebulization is stoppedwhen the patient is not inhaling.

BRIEF SUMMARY

In an embodiment, this invention provides a breath triggered gas jetnebulizer comprising a generally cylindrical body in a horizontalorientation to the patient. Within the body is a Venturi configured tonebulize a solution of a drug stored in a reservoir. Within the body isa shaft integrated with a baffle and diaphragm that moves horizontallyin response to the breathing of a patient. When the patient is inhalingthe diaphragm flexes shifting the baffle toward the patient and over theVenturi, allowing nebulization to occur. When the patient's inhalationstops, the diaphragm flexes to a default position in which the baffle isshifted to a position distal to the Venturi, thereby stopping thenebulization.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-section of the nebulizer in the nebulization mode.

FIG. 1B is a cross-section of the nebulizer in the non-nebulizationmode.

FIG. 1C is a detail cross-section of a portion of FIG. 1B

FIG. 2A is an exploded view from an anterior viewpoint.

FIG. 2B is an exploded view from a posterior viewpoint.

FIG. 3A is a perspective view of the assembled nebulizer from ananterior viewpoint.

FIG. 3B is an elevation view of the front (anterior) end of thenebulizer.

FIG. 3C is a perspective view of the assembled nebulizer from anposterior viewpoint.

FIG. 4A is a perspective view of the inventive nebulizer with aninhalation mask connected to the airway of the nebulizer.

FIG. 4B is a different perspective view of the inventive nebulizor withan inhalation mask connected to the airway of the nebulizer.

FIG. 5A is a perspective view of the inventive nebulizer with amouthpiece connected to the airway of the nebulizer.

FIG. 5B is a different perspective view of the inventive nebulizer witha mouthpiece connected to the airway of the nebulizer.

DETAILED DESCRIPTION

The nebulization action in the gas jet nebulizers disclosed herein foradministering medication to humans or animals by inhalation depends on adevice with a reservoir containing a solution with a drug dissolvedtherein, and a Venturi effect with a high pressure jet orifice and oneor more liquid orifices adjacent to the jet, wherein a baffle ordeflector impinges on the jet a short distance above the jet orifice.One or more liquid orifices adjacent to the Venturi orifice are incommunication with liquid tubes or capillaries fed by a drug reservoircontaining a solution of drug. The nebulization or aerosolization (theseterms are used interchangeably herein), presumably occurs because thebaffle deflects the low pressure zone created by the Venturi over theliquid orifices. Without being bound by any theory of operation, it isbelieved that the reduced pressure created by the Venturi jet impingingon the baffle draws the drug solution through the liquid orifices, andthe jet aerosolizes the liquid as it exits the liquid orifices fromshearing effects. The baffle typically also performs a secondaryfunction of deflecting large droplets and forcing them back into thedrug reservoir, since in a drug nebulizer, only very small droplets thatfreely float in air are desired as an inhaled aerosol. Without thebaffle, the liquid orifices are presumably not subject to the effect ofthe Venturi low pressure zone and no liquid is drawn out of the liquidorifices, and no aerosolization occurs. Thus, in this invention, amovable baffle is provided in a horizontal plane, such that when thebaffle is directly over the Venturi, nebulization occurs, and when thebaffle is moved horizontally away from the Venturi, nebulization stops.In this invention, by moving the baffle into a nebulizing position inresponse to the inhalation of a patient, the nebulization only occurswhen the patient is inhaling, and no nebulization occurs when thepatient is exhaling or otherwise not exerting an inhalation. Thismovement of the baffle that creates or stops nebulization is termed“breath triggered” or “breath actuated” (which terms are usedinterchangeably) nebulization.

In an embodiment of this invention, a breath triggered nebulizer isprovided for the administration of inhaled medication to a patient, saidnebulizer having horizontal and vertical axes, comprising a horizontallyoriented cylindrical body defining an upper chamber airway; a verticallyoriented lower chamber having therein a liquid reservoir containing amedicament in solution, wherein said liquid reservoir defines thehorizontal axis; a pressurized gas inlet port in fluid communicationwith a gas jet; a liquid channel surrounding the gas inlet port, saidliquid channel in fluid communication with a liquid orifice, wherein thegas jet is adjacent to the liquid orifice, and the gas jet is orientedvertically; a horizontally movable baffle comprising a first position ata predetermined distance from the gas jet such that a pressuredifferential is created in the liquid channel that draws liquid throughthe liquid channel and causes nebulization by the interaction of the gasjet and liquid orifice; wherein the baffle has a second default positiondistal from the gas jet such position at a distance from the gas jet sothat the pressure differential is insufficient to draw liquid into theliquid channel, and no nebulization of the liquid occurs; wherein thebaffle movement is controlled by a horizontal channel between the firstand second positions at a fixed vertical distance relative to the gasjet; and wherein the baffle is moved from the second position to thefirst position by the inhalation by the patient, and the baffle shiftsto the second position when the patient is not inhaling.

Thus, the inventive nebulizer 10 in the Figures has defined horizontaland vertical axes. In one aspect, the horizontal axis is defined by thedrug reservoir 112, which must generally remain generally level becauseit contains a liquid. In another aspect, the horizontal axis may bedefined by a line through the center of the generally cylindrical body100, from the airway end 104 to the back of the apparatus at cap 130.Thus, as shown in FIGS. 1A and 1B, the horizontal and vertical axes areas drawn, i.e., the vertical axis is top to bottom, and the horizontalaxis is right to left. Thus, cap 150 is at the top of the device, andlower body 110 is at the bottom of the device.

Body 100 of the nebulizer 10 comprises a main section that iscylindrical in shape, is oriented horizontally, and defines an interiorchamber 101. The ventral side of body 100 has a circular opening 106connected to lower body 110. Lower body 110 includes a drug reservoir112 that in operation would be filled with a liquid medication.Reservoir 112 is a cup shaped vessel that narrows at the bottom andfeeds the drug solution into opening 820 for inspiration into theVenturi.

The Venturi is integral with lower body 110. The Venturi comprises apressurized gas inlet stem 116 and pressurized gas tube 115. At the topof tube 115, at least one liquid window 330 is provided, with section332 above the window. Tube 115 narrows in the conical section 117,leading to Venturi orifice 310. A passageway 336 is defined betweensection 332 and section 117. At the top of passageway 336 is one or moreliquid orifices 312 through which the drug solution will pass duringnebulization. Stem 144 fits over tube 115, defining a narrow passageway335 for the drug solution to pass during nebulization. The drug solutionis fed into passageway 885 through an opening 320 at the bottom of stem144. During nebulization, the drug solution is drawn through opening820, up passageway 335, and through windows 330. The drug solution thenmoves into passageway 336 and exits from orifices 312. The drug solutionis then aerosolized in the space of chamber 101 on exposure to the highvelocity low pressure local environment in the Venturi duringnebulization.

In an embodiment, the Venturi orifice 310 and the orifices 312 aresituated on a planar surface 313 and all of orifices 310 and 312 are onthe same plane.

The dorsal side of body 100 may contain a circular opening 108 which iscovered by top cap 150. Top cap 150 is intended to be easily removable,and can be used to add the drug solution to the reservoir 112 with apipette or by simply pouring a solution of drug into the reservoir 112.

The anterior end of body 100 (the end closest to the patient) comprisesopening 104 which defines the airway 105 by which aerosolized drug isexhausted from the nebulizer during inhalation into the mouth or nose ofa patient. The aerosolized drug then travels to the lungs of the patientduring inhalation. In an embodiment, baffle 109 is situated in theairway aft of opening 105. If present, baffle 109 blocks about the lowerthird of opening 105, and helps to ensure that only freely floatingaerosol particles are inhaled by the patient. Baffle 109 helps to blockthe ingestion of larger aerosol particles from being inhaled.

In an embodiment, as illustrated in the drawings, opening 105 is incommunication with adapter 400 and swivel adapter 410. A mouthpiece ormask may be connected to airway 430 on swivel adapter 410 in thisembodiment. Also shown is exhaust valve 420, in the illustratedembodiment integrated to adapter 400. An embodiment of exhaust valve 420is shown with flap 422, made from a flexible rubber material thatprovides a tight seal during inhalation but flexes open to exhaustexhaled air during exhalation. Other configurations of the exhaust valveare possible. An exhaust valve is necessary in this nebulizer becausethere is no other vent or pressure equalization provided in body 100 forexhaled air.

The posterior end of body 100 comprises a circular opening 102 that isconnected end cap 130. A series of vents 132 are in cap 130. A series ofone-way vents 132 are in cap 130 that permit air to enter to equalizepressure during inhalation, but are sealed during exhalation.

Channel support 140 is an integrated part that includes vertical shaft144 and cap portion 142. Shaft 144 defines a pipe that nests over gastube 115. The space between shaft 144 and tube 116 is liquid passage335. Cap portion 142 contains baffle guide channels 148 and 149.Alignment tab 146 protrudes from vertical shaft 144 on the left side asillustrated in FIG. 2A, and serves to align support 140 with respect tothe movable baffle. Tab 146 fits into slot 147 on lower body 110.

Within body 100 is integrated shaft assembly 200, which includesdiaphragm 210 and the Venturi baffle 202. Diaphragm 210 is supportedperipherally by ring 212, which is torsionally inflexible, and nests inindents 122, part of body 100. The diaphragm 210 is made from a flexiblematerial such as a soft rubber, and can easily flex in response to thepatients breathing. The center of diaphragm 210 is connected to shaft200. The anterior end of shaft 200 contains supports 205 and 206. Guideskid 204 is connected to 205, and baffle 202 is connected to 206. Theposterior end of baffle 202 contains tab 203, that acts as a backstop,preventing further forward motion of shaft 200 during inhalation, whenthe shaft moves forward.

This nebulizer is termed “breath triggered” because the action ofinhalation during use starts nebulization of a drug, and nebulization ofthe drug ceases when inhalation ceases, either during exhalation or anyother point when the patient is not inhaling, that it, drawing air intothe patients' lungs naturally. During inhalation, the breathing actioncreates a negative pressure in the chamber 101 of the nebulizer 10. Thisflexes the diaphragm 210 forward, which moves baffle 202 from thedefault non-nebulization position to the nebulization position, byshifting the integral shaft 200 and movable baffle 202 to a positiondirectly over the Venturi jet, thereby causing aerosolization to occurwhen the liquid orifices 312 are subject to the high velocity lowpressure local environment from the Venturi. This movement isillustrated by cross-section views in FIGS. 1B and 1A. FIG. 1B is thedefault, non-inhalation position. The diaphragm is biased to theposition as shown in FIG. 1B when no inhalation is occurring. Duringinhalation, the negative pressure in chamber 101 draws diaphragm 210forward, as shown in FIG. 1A, and moves shaft 200 and baffle 202 tocause nebulization to occur. The diaphragm must be designed to besufficiently sensitive to low inhalation flow velocities, for examplefrom highly diseased persons with very weak inspiratory ability, orsmall children, yet still provide sufficient force to move the shaft tothe nebulization position. In an embodiment, the diaphragm may bedesigned to move within a range of inhalation flow rates of 0.5 L/min innew born infants to 15 L/min in adults.

When inhalation ceases, the diaphragm flexes in a posterior direction toits default position, returning to the configuration shown in FIG. 1B,drawing movable baffle 202 rearward so that the Venturi jet is ventedinto the space between supports 205 and 206. Without the baffle directlyover the Venturi, no nebulization occurs, because the jet vents directlyupward, and the liquid orifices 312 are not subject to the Venturieffect, so no liquid is drawn through the orifices 312.

The vent ports 120 equalize pressure during inhalation, preventing avacuum from developing in the main body of the nebulizer. Flexible flaps220, which are integral with the diaphragm 210 rest in indents insection 122, and cover ports 120 from the interior chamber 101. Duringexhalation or when breathing is relaxed, the flaps prevent air andaerosolized drug in the interior chamber 101 from escaping from thenebulizer. During inhalation, the negative pressure in the interiorchamber 101 opens the flaps to equalize the air pressure in the chamber101.

In an embodiment, a noise making feature may be provided that makes aclicking sound during inhalation. As shown in the figures, this maycomprise protrusion 230 that rests in cavity 134 on the interior of endcap 132. During inhalation, when the shaft assembly 200 is drawnforward, the action of protrusion 280 moving in cavity 184 may make aclicking sound. In an embodiment, when the shaft assembly 200 moves backto its default position during exhalation, 230 and 134 hit each othermaking a clicking sound.

The interface with the inventive apparatus and the patient is amouthpiece or inhalation mask. A mouthpiece may comprise variousembodiments. In an embodiment, a mouthpiece may be a generallycylindrical or ovoid (in cross section) appendage suitable for insertioninto the mouth of the patient. The patient then wraps his or her lipsaround the mouthpiece to make a seal and proceeds to inhale and exhaleto receive the nebulized drug. In another embodiment, a mouthpiece mayhave a flattened portion for insertion into the mouth and lips.

In another embodiment, an inhalation mask may be employed that coversthe mouth and/or nose of the patient. The mask would have a suitableinlet for connecting to airway 105 to receive the nebulized medicationthat is transmitted to the mouth and/or nose of the patient. Smallchildren, in particular, are obligate nasal breathers. In the case of aninhalation mask, an exhaust valve is mandatory, because there is nopressure equalization outlet in the inventive nebulizer apparatus tovent exhaled air. Such an exhaust valve may be integrated into the mask,or it may be on a linking part between the nebulizer and the mask, shownfor example as part 420 in the drawings. With any exhaust valveembodiment, a further optional embodiment is a filter to trap andprevent substantially all of the active drug from entering the outsideair in front of the patient. In some case, active drug can harm nearbypersons including caregivers, and may even harm the patient, for exampleby causing eye irritation. The use of a filter can prevent this problem.

Various embodiments of the inventive nebulizer and a mouthpiece orinhalation mask are shown in FIGS. 4 and 6. FIGS. 4A and 4B show aninhalation mask connected to the inventive nebulizer with a swiveladapter. A variety of masks may be employed with the inventivenebulizer. The mask shown in FIGS. 4A and 4B is described ininternational patent application PCT/US2012/042055, and has a sootherdevice orifice, through with a nipple may be inserted for use with asmall child who would suck on the nipple while inhaling medicationthrough the mask with an airway aligned with nose of the patient. Inanother embodiment (not shown), the mask may not have a soother deviceorifice.

FIGS. 5A and 5B illustrate the nebulizer with a mouthpiece that acompetent older child or adult would typically use. The mouthpiece isinserted into the mouth of the patient and the patient forms a sealaround the mouthpiece with their lips while inhaling a drug using thenebulizer. By the term “competent” it is meant here that the patient isconscious and can accept and understand instructions.

By the term “medicament” as used herein is meant a drug suitable foradministration directly into the lungs of a patient.

This invention provides both a nebulizer apparatus 10 and a method ofadministering a drug to a patient with a nebulizer 10. In the method ofadministering a drug to a patient, a solution of a drug is added toreservoir 112 through opening 152, a source of pressurized medical gas,such as air or medical oxygen is connected to stem 116. In variousembodiments, a mouthpiece fitted to the inventive nebulizer is insertedinto the patients mouth, or a mask is connected to the nebulizer that isheld by a caregiver over the mouth and nose of a patient. When thepatient inhales, the nebulizer 10 will provide atomized drug that willenter the lungs of the patient. When the patient is not inhaling, suchas during an exhalation or during periods when the patient is neitherinhaling nor exhaling, the atomization stops. Accordingly, there isminimal wasted drug as compared to conventional nebulizers that nebulizedrug continually regardless of whether a patient is inhaling or not, andthe dose of the drug can be more accurately determined, since there isminimal wastage.

What is claimed is:
 1. A breath triggered nebulizer for theadministration of inhaled medication to a patient, said nebulizer havingan upper chamber airway and horizontal and vertical axes, comprising: a)a horizontally oriented cylindrical body defining an upper chamberairway, said horizontal oriented cylindrical body has a distal end and aproximal end; b) a vertically oriented lower chamber having therein aliquid reservoir containing a medicament in solution, wherein saidliquid reservoir defines the horizontal axis; c) a pressurized gas inletport in fluid communication with a gas jet; d) a liquid channelsurrounding or adjacent the gas inlet port, said liquid channel in fluidcommunication with a liquid orifice, wherein the gas jet is adjacent tothe liquid orifice, and the gas jet is oriented vertically; e) ahorizontally movable shaft assembly within the upper chamber airway, theshaft assembly comprising a flexible diaphragm distal from the gas jetand a baffle at an end of the shaft assembly opposite the flexiblediaphragm, said flexible diaphragm being located at said distal end ofthe horizontally oriented cylindrical body, the shaft assembly furthercomprising (i) a first position wherein the baffle is at a predetermineddistance from the gas jet such that a pressure differential is createdin the liquid channel that draws the medicament solution through theliquid channel and causes nebulization of the medicament solution by theinteraction of the gas jet and liquid orifice, and (ii) a secondposition wherein the baffle is at a distance distal from the gas jetsuch that the pressure differential is insufficient to draw liquid intothe channel and no nebulization occurs; f) whereby the baffle movementis controlled by a tab extending from the shaft assembly between thefirst position and the second position at a fixed vertical distancerelative to the gas jet; g) whereby the shaft assembly is moved from thesecond position to the first position during inhalation by the patientwhich flexes the diaphragm in a forward direction, and whereby the shaftassembly shifts to the second position when the patient is not inhaling,which flexes the diaphragm in a posterior direction to a posteriorposition; and h) wherein the nebulized medicament solution is inhaled bythe patient thereby delivering nebulized medicament solution to lungs ofthe patient, said nebulizer further comprising a breath enhanced valvesystem comprising a one-way vent that opens during inhalation to permitexternal air entry into the upper chamber and further comprising aninhalation mask or mouthpiece in fluid communication with the upperchamber airway.
 2. The nebulizer of claim 1 wherein an audio signal isproduced when the shaft assembly moves from the first position to thesecond position.
 3. The nebulizer of claim 2 wherein the shaft assemblyfurther comprises a protrusion at the distal end of the shaft assemblycomprising the flexible diaphragm, the nebulizer further comprising anend cap adjacent the flexible diaphragm, wherein the audio signal is aclicking sound produced by the protrusion contacting a part of the endcap.
 4. The nebulizer of claim 1 wherein said gas jet and liquid orificeare on the same horizontal plane.
 5. The nebulizer of claim 1 whereinthe liquid orifice comprises one or more holes on top of the liquidchannel.
 6. The nebulizer of claim 1 wherein the liquid orificecomprises a concentric tubular opening in a concentric relationship tothe gas jet.
 7. The nebulizer of claim 1 wherein the baffle isresponsive to inspiratory flow velocity in the range of 0.5 L/min to 15L/min.
 8. The nebulizer of claim 1 wherein an exhalation valve ispresent on the upper chamber airway.
 9. The nebulizer of claim 8 whereinthe exhalation valve has a filter that traps substantially all exhaledmedication from being expelled from the nebulizer.
 10. A method ofadministering an inhaled medicament to a patient with a nebulizercomprising: a) providing the nebulizer of claim 1; b) inhaling air fromthe horizontally oriented cylindrical body to flex the diaphragm andmove the shaft assembly from the second position to the first position;c) creating a pressure differential in the liquid channel to draw themedicament solution through the liquid channel causing the nebulizationof the medicament solution; and d) transmitting the nebulized medicamentsolution to the lungs of the inhaling patient.